Boiler



' Dec. 27, 1938. F. R. DALY r BOILER Filed July 26, 1937 2 Sheet-Sheet- 1 fizmnzor DAL Y Hem/as 1 MM Y A flfTqeA/EK:

Dec. 27,1938. 7 v F. R. DALY BOILER I Filed July 26/1937 2 Sheets-Sheet 2 [Ml/e22 for I Femvc/s k. DAL Y Patented Dec. 27, 1938 UNITED STATES PATENT OFFICE BOILER Francis R. Daly, Minneapolis, Minn. Application July 26, 1937, Serial No. 155,711

6 Claims.

This invention relates to new -and.useful improvements in boilers, generally, and more particularly to boilers of the type used for heating buildings, homes, and the like.

An object of the! invention is to provide a boiler which is so constructed that substantially all the heat of the products of combustion is efiiciently absorbed by the water, whereby the latter may be quickly heated to the desired temperature,

10 or, if desired, to a temperature for generating steam.

A further object is to provide a boiler comprising an outer drum and an inner drum, the

latter being relatively smaller in diameter and length, thereby to provide a water jacket around the .inner drum, and said inner drum having a combustion chamber therein.

A further object is to provide a boiler of the character described comprising two drums of different diameters the smaller one being mounted within the larger drum in eccentric relation thereto, and with its walls spaced from the corresponding walls of the outer drum to provide an annular water jacket around the inner drum, and

a bank of water heating and circulating tubes being connected with the water jacket below the inner drum, and formed with a U-bend disposed within the inner drum,-the discharge ends of said tubes communicating with the water jacket above 80 the inner drum, and a combustion chamber being provided within the inner drum, whereby portions of the water circulating tubes disposed therein are subjected to the direct heat of the products of combustion.

A further object is to provide a boiler comprising an outer drum or shell having a relatively smaller drum mounted therein and off-set from the axis thereof, and the inner drum being supported at one end in such a manner that it may freely expand or contract longitudinally with respect to the outer drum, without danger of damaging any of the joints or connections of the boiler.

A further object is to provide a boiler of the class described comprising an inner drum supported at one end with its walls spaced from the corresponding walls of the outer drum to provide an annular water jacket, and an upwardly arched wall being provided within the inner drum,

extending lengthwise therein and providing the bottom wall of a combustion chamber, other walls of said chamber being defined by portions of the cylindrical wall of said inner drum, and a bank of water circulating tubes having their receiving &5 ends communicating with the water jacket below the inner drum and extending lengthwise of the inner drum, beneath said arched wall, then upwardly and forwardly from the rear end of the inner drum and having their discharge ends communicating with the water jacket above the inner 5 drum portions of said tubes, whereby said tubes are subjected to the direct heat of the products of combustion, and a vertically disposed baffle plate being provided at the rear end of said arched wall in spaced relation to the end wall of the inner drum for directing the products of combustion upwardly between said tubes: and downwardly through a smoke passage provided between the baflle plate and the .rear wall of the inner drum and which passage extends forwardly 15 beneath the said arched wall and communicates with a smokeduct disposed beneath the outer drum, and which is connected to a suitable smoke stack chimney, or suction fan.

Other objects of the invention reside in the 20 unique arrangement of the inner and outer drums which facilitates manufacture and minimizes the danger of leakage, caused by expansion or contraction of the inner drum, due to varying temperature; in the unique construction of the com- 25 bustion chamber within the inner drum, whereby a smoke passage is provided beneath the combustion chamber, which extends the full length of the inner drum, so that the heat of the products I Water circulating tubes and the construction of the furnace, whereby the bottom wall of the combustion chamber, the baflle plate provided at the rear end thereof, and the water circulating tubes, may be removed from the inner drum, as a unit; in the unique arrangement of the receiving and discharge ends of the water circulating tubes, whereby uniform circulation of the water is obtained throughout the entire boiler; and, in the 45 construction of the water circulating tubes, whereby the U-shaped portions thereof which are disposed within the combustion chamber, may be removed from said chamber without removing the intake and discharge ends of the tubes from 50 the water jackets, thereby greatlysimplifying the operation of removing the tubes for repairs or replacement, when necessary.

Other objects of the invention will appear from the following description and accompanying drawings and will be pointed out in the annexed claims.

In the,- accompanying drawings, there has been disclosed a structure designed to carry out the various objects of the invention, but it is to be understood that the invention is. not confined to the exact features shown as various changes may be made within the scope of the claims which follow.

In the drawings,

Figure 1 is a vertical sectional view on the line i! of Figure 2, showing the unique arrangement of the inner drum within the outer drum, and also the arrangement of the water circulating tubes within the boiler;

Figure 2 is a cross sectional view on the line 2 2 of Figure 1, showing the preferred arrangement of the water circulating tubes within the boiler, and the means provided within the inner drum for providing a combustion chamber;

Figure 3 is a sectional plan view substantially on the line 33 of Figure 1, showing the stepped arrangement of the receiving and discharge ends of the water circulating tubes;

Figure 4 is a view showing the preferred shape of the intermediate portions of the water circulating tubes; and

Figure 5 is. an enlarged detail sectional view on the line 55 of Figure 4.

The novel boiler herein disclosed is shown comprising an outer drum or shell, generally indicated by the numeral 2, and comprising a cylindrical Wall 3, rear wall 4, and front wall 5. Outlet connections 6 are shown provided in the upper portion of the drum 4 for conducting steam or hot water to the usual heat exchange units or radiators, not shown. The usual return connection "I is shown provided in the bottom wall of the outer drum 2, as best illustrated in Figure l.

A feature of the present invention resides in the interior construction of the boiler, which, as best illustrated in Figures 1 and 2, includes an inner drum 8. The inner drum is relatively smaller in diameter than the outer drum, and is also shorter in length, whereby an annular water chamber 9 is provided between the walls of the two drums, as best illustrated in Figure 2. The inner drum has its front end suitably secured to the front wall 5 of the outer drum 2. The opposite end of the inner drum 8 is unsecured, whereby said inner drum, is free to expand or contract longitudinally with respect to the outer drum without danger of causing leakage in the joints and connections of the boiler, which might occur if the inner end of the drum 8 were also fixedly secured to the outer drum. If desired, however, the inner end of the drum 8 may be supported upon a suitable rest, not shown in the drawings, which will permit said drum to expand or contract longitudinally with respect to the outer drum 2. The front end of the inner drum 8 may be conveniently secured to the front wall 5 by such means as welding, whereby the inner drum becomes, in effect, an integral part of said front wall 5 and the outer drum 2, which is also preferably welded to the front wall 5.

To provide efficient and rapid circulation of the water through the boiler, a bank of water circulating tubes, generally indicated by the numeral ii, is provided within the inner drum 8, and has lower horizontal tube portions l2 extending substantially the full length of the inner drum, in spaced relation to the lowermost portion of the wall thereof, as clearly illustrated in Figures 1 and 2. The lower tube portions l2 have their receiving ends. shaped as shown at l3 in Figure 1, and coupled to a plurality of tubes M, by suitable couplings l5. The tubes M are disposed in the water jacket beneath the inner drum 8, and have their forward portions l6 secured in fixed relation to the front wall 5, whereby the tubes are supported substantially as shown in Figures 1 and 2.

The rear ends: of the horizontal tube portions l2 are bent upwardly and preferably forwardly, as shown at I! in Figure l, and merge into horizontal tube portions l8, whose front ends are bent, 2. shown at l9 and have couplings 2! connecting them to a plurality of tubes 22, disposed in the water jacket directly above the inner drum 8. The tube sections 22 have their forward ends secured to the front wall 5 in a manner similar to the lower tube sections I4, and provide the discharge ends of the bank of tubes H.

Another feature of the invention resides in the unique arrangement of the intake and discharge ends of the tube sections l4 and 22, forming the receiving and discharge ends of the bank of tubes l I. These tubes are preferably arranged, as shown in Figure 3, whereby it will be noted that they vary in length. By thus varying the length of the tube sections I4 and 22, uniform circulation of all of the water in the water jacket is obtained, as it eliminates dead ends or spaces Where the water might otherwise remain stagnant. In Figure 3, the arrows indicate how uniform circulation through the boiler is obtained as a result of the water discharging from the pipe sections 22 at spaced intervals along the length of the boiler. The receiving ends or pipe sections M of the bank of tubes II being similarly arranged, cause the water to enter the bank of tubes along the full length of the boiler.

Another feature of the invention resides in the construction of the furnace or combustion chamber. As best illustrated in Figures 1 and 2, the combustion chamber, generally indicated by the numeral 23 is provided within the inner drum 8, and is defined by a portion of the cylindrical wall of the drum 8, and a longitudinally extending wall 24 disposed within the drum 8 in spaced relation from the lowermost wall portion thereof. The wall 24 is preferably arch-shaped, as best illustrated in Figure 2, and is composed of a suitable refractory material or brick 25, which is shown supported on a metallic plate 26, whose side edges are supported on the wall of the drum 8, as clearly illustrated in Figure 2.

A baflie plate 2'! is provided at the rear end of the arched wall 24 and extends upwardly therefrom in spaced relation to the end wall 28 of the inner drum, as best illustrated in Figure 1, thereby providing a smoke passage 29 between the bafiie 21 and end wall 28. The lower end of the smoke passage 29 communicates with a horizontal smoke passage 3! provided between the arched wall 24 and the lower wall portion of the inner drum 8. The front end of the smoke passage 3! communicates with one end of a smoke duct 32, disposed directly beneath the outer drum 2, and the opposite end of which may be connected to a suitable smoke stack, chimney or suction fan, not shown in the drawings. A bypass damper 33 is shown provided between the smoke passage 31 and smoke duct 32. By means of this by-p-ass, the fiow of hot gases through the smoke duct 32 may be controlled, so that all of the heat thereof may be utilized, resulting in greater economy.

The unique arrangement of the water circulating tubes 1 I, the furnace, and the smoke passages for conducting the smoke from the combustion chamber to the stack, provide an important feature of the present invention. By reference to Figures 1 and 2', it will be noted that the horizontal portions l2 of the bank of tubes I I are disposed within the smoke passage 3|, whereby the heat of the products of combustion passing therethrough, will be absorbed by the water in said tube portions utilizing the counter flow principle of heat transfer. It is also to be noted that the lower wall portion of the inner drum 28 and the corresponding wall portion of the outer drum 2 are in direct contact with the products of combustion passing through the passage 3|, duct 32 to the smoke stack. By thus causing the smoke to travel downwardly through the passage 29, thence forwardly through the passage 3! and finally, rearwardly to the smoke outlet, substantially all of the heat in. the products of combustion is absorbed by the water in the boiler before the smoke reaches the stack. By such efiicient and complete transfer of the heat from the products of combustion to the water, a very efiicient and economical boiler is provided in which the heat loss becomes a negligible quantity.

In manufacturing the novel boiler herein disclosed, the bank of tubes II, as best shown in Figures 1 and 4, are bent to shape and then fastened, by suitable U-shaped elements or bolts 35 tothe arched plate 26 to which the bafiie plate 21 is attached. Then the plastic or moulded refractory material 25 is placed on the arched plate 26, and the complete assembly inserted into the inner drum 8, after which the unions I 5 and 2| are connected to the respective circulating pipes l4 and 22. When repairs are necessary, the entire assembly is withdrawn from the inner drum.

The novel boiler herein disclosed is extremely simple and inexpensive in construction. The tubes H are preferably of copper and are spaced apart, as illustrated in Figure 2, to provide rapid circulation, added heating surface and quick steaming.

In operation, the products of combustion which preferably is derived from a suitable oil burner or stoker, pass between the inclined tube portions l1, whereby it directly contacts the walls thereof and also the walls of the tubes I8, after which it passes over the top of the bafiie plate 21, as indicated by the arrows in Figure l. The hot furnace gases then pass downwardly through the passage 29 and forwardly through the smoke passage 3I, whereby the major portion of the heat in said gases is absorbed by the horizontal pipe portions I2 disposed in the upper portion. of the smoke passage 3|, as clearly illustrated in Figures 1 and 2. From the smoke passage 3|, the smoke travels downwardly and into the smoke duct 32 to the smoke outlet or stack, not shown in thedrawings. As a result of the smoke or products of combustion being in direct contact with the walls of the inner and outer drums, until it reaches the rear end portion 35 of the smoke duct- 32, substantially all of the heat in the furnace gases will be absorbed by the water in the boiler, which results in the production of a very efficient and economical boiler structure.

7 I claim as my invention:

1. In a boiler of the class described, an outer drum, a relatively smaller drum mounted within the outer drum and having its horizontal wall and one end spaced from the corresponding walls of the outer drum to provide a water jacket, said inner drum providing a combustion chamber, and a bank of water-circulating tubes disposed within the inner drum and having their receiving and discharge ends connected respectively with the water jacket below and above the inner drum, portions of said tubes extending lengthwise through the inner drum and having means cooperating therewith to provide the bottom wall of the combustion chamber.

2. In a boiler of the classdescribed, an outer drum, a relatively smaller drum mounted within the outer drum and having certain of its walls spaced from the corresponding walls of the outer drum to provide a water jacket, a combustion chamber in the inner drum, and a bank of water circulating tubes of substantially U-shaped form disposed within the inner drum and having their receiving and discharge ends connected respectively with the water jacket below and above the inner drum, the receiving and discharge end portions of said tubes progressively varying in length, lengthwise of the boiler, thereby as to cause uni form circulation throughout the boiler.

3. In a boiler of the class described, an outer drum,a relatively smaller drum mounted within the outer drum and having certain of its walls spaced from the corresponding walls of the outer drum to provide a water jacket, means within the inner drum providing a combustion chamber and including a suitable wall disposed in the lower portion of the inner drum and cooperating with a wall thereof to provide a horizontal smoke passage, a bafiie plate disposed adjacent the rear wall of the inner drum and spaced therefrom to provide a vertically disposed smoke passage for establishing communication between the combustion chamber and said horizontal smoke passage, and a bank of water-circulating tubes having their lower ends communicating with the water jacket below the inner drum, and theirupper ends with the water jacket above the inner drum, the intermediate portions of said bank of tubes passing through the combustion chamber.

4. In a boiler of the class described, an outer drum, a relatively smaller drum mounted within the outer drum and cooperating therewith to provide a water jacket, a longitudinally extending wall in the lower portion of the inner drum cooperating with certain of the walls thereof to provide a combustion chamber, a horizontal smoke passage defined by said horizontal wall and the bottom wall of the inner drum, a baffle plate disposed adjacent the rear end of the inner drum and spaced therefrom to provide a vertically disposed smoke passage communicating with said horizontal smoke passage, a bank of water circulating tubes communicating with the water jacket below and above the inner drum and having portions extending into the combustion chamber in the inner drum, thereby speeding up the circulation of water through said tubes, and means below the outer drum providing a smoke duct which communicates with said horizontal smoke passage at the front end of the boiler, and having its opposite end adapted for connection to a smoke outlet at the rear end of the boiler.

5. In a boiler of the class described, an outer drum, an inner drum supported within the outer drum in a manner to permit free longitudinal expansion and contraction thereof with respect to the outer drum, a substantially horizontally disposed wall extending lengthwise through said inner drum and having its rear end spaced from the rear wall thereof, said horizontal wall oooperating with the upper walls of the inner drum to provide a combustion chamber in the inner drum, a longitudinally extending smoke passage in the inner drum beneath said horizontal Wall, a bafile plate cooperating with the rear wall of the inner drum to provide a vertical smoke passage connecting the upper rear portion of the combustion chamber with the rear end of said horizontal smoke passage, and a plurality of water-circulating tubes having their receiving ends communicating with the water jacket beneath said inner drum and having portions passing l ngthwise through said horizontal smoke passage, thence upwardly and forwardly through the combustion chamber, and having their discharge ends connected to the water jacket above the inner drum, portions of said tubes passing through the combustion chamber, whereby the water therein is quickly heated to insure rapid circulation of the water through the boiler.

6. In a boiler, an outer drum, an inner drum supported within the outer drum with its cylindrical wall and one end wall spaced from the corresponding walls of the outer drum to provide a water jacket, a refractory wall in the lower portion of the inner drum cooperating with the walls thereof to provide a combustion chamber having a smoke passage therebeneath extending substantially the length of the inner drum, said refractory wall having its inner end spaced from the adjacent end of the inner drum, a baflle extending upwardly from the inner end of said refractory wall and cooperating with the inner end of the inner drum to provide a down-draft smoke outlet communicating with said smoke passage, means connecting the 'front end of said smoke passage to one end of an external smoke duct, the opposite end of which is connected to a suitable smoke outlet, and a bank of water circulating tubes having their lower ends connected to the water jacket below the inner drum and their upper ends to the water jacket above the inner drum, the intermediate portions of said tubes extending longitudinally into the combustion chamher and so arranged therein that they are free to expand or contract in all directions, said smoke passage and tubesv being so arranged that the furnace gases travel in a direction opposite to the flow of water through the lower portions of said tubes, whereby maximum heat absorption by the water is obtained.

FRANCIS R. DALY. 

